PURPOSE: The primary purpose of this systematic review is to synthesize the evidence regarding risk factors associated with nonadherence to prescribed glucose-lowering agents, the impact of nonadherence on glycemic control and the economics of diabetes care, and the interventions designed to improve adherence.
METHODS: Medline, EMBASE, the Cochrane Collaborative, BIOSIS, and the Health and Psychosocial Instruments databases were searched for studies of medication adherence for the period from May 2007 to December 2014. Inclusion criteria were study design and primary outcome measuring or characterizing adherence. Published evidence was graded according to the American Association of Clinical Endocrinologists protocol for standardized production of clinical practice guidelines.
RESULTS: One hundred ninety-six published articles were reviewed; 98 met inclusion criteria. Factors including age, race, health beliefs, medication cost, co-pays, Medicare Part D coverage gap, insulin use, health literacy, primary nonadherence, and early nonpersistence significantly affect adherence. Higher adherence was associated with improved glycemic control, fewer emergency department visits, decreased hospitalizations, and lower medical costs. Adherence was lower when medications were not tolerated or were taken more than twice daily, with concomitant depression, and with skepticism about the importance of medication. Intervention trials show the use of phone interventions, integrative health coaching, case managers, pharmacists, education, and point-of-care testing improve adherence.
CONCLUSION: Medication adherence remains an important consideration in diabetes care. Health professionals working with individuals with diabetes (eg, diabetes educators) are in a key position to assess risks for nonadherence, to develop strategies to facilitate medication taking, and to provide ongoing support and assessment of adherence at each visit.
BACKGROUND: Poor adherence to anti-diabetic medications contributes to suboptimal glycaemic control in patients with type 2 diabetes (T2D). A range of interventions have been developed to promote anti-diabetic medication adherence. However, there has been very little focus on the characteristics of these interventions and how effectively they address factors that predict non-adherence. In this systematic review we assessed the characteristics of interventions that aimed to promote adherence to anti-diabetic medications.
METHOD: Using appropriate search terms in Medline, Embase, CINAHL, International Pharmaceutical Abstracts (IPA), PUBmed, and PsychINFO (years 2000-2013), we identified 52 studies which met the inclusion criteria.
RESULTS: Forty-nine studies consisted of patient-level interventions, two provider-level interventions, and one consisted of both. Interventions were classified as educational (n = 7), behavioural (n = 3), affective, economic (n = 3) or multifaceted (a combination of the above; n = 40). One study consisted of two interventions. The review found that multifaceted interventions, addressing several non-adherence factors, were comparatively more effective in improving medication adherence and glycaemic target in patients with T2D than single strategies. However, interventions with similar components and those addressing similar non-adherence factors demonstrated mixed results, making it difficult to conclude on effective intervention strategies to promote adherence. Educational strategies have remained the most popular intervention strategy, followed by behavioural, with affective components becoming more common in recent years. Most of the interventions addressed patient-related (n = 35), condition-related (n = 31), and therapy-related (n = 20) factors as defined by the World Health Organization, while fewer addressed health care system (n = 5) and socio-economic-related factors (n = 13).
CONCLUSION: There is a noticeable shift in the literature from using single to multifaceted intervention strategies addressing a range of factors impacting adherence to medications. However, research limitations, such as limited use of standardized methods and tools to measure adherence, lack of individually tailored adherence promoting strategies and variability in the interventions developed, reduce the ability to generalize the findings of the studies reviewed. Furthermore, this review highlights the need to develop multifaceted interventions which can be tailored to the individual patient's needs over the duration of their diabetes management.
Previous reviews have shown that changes in prescription drug insurance benefits can affect medication use and adherence. We conducted a systematic review of the literature to identify studies addressing the association between prescription drug coverage and health outcomes. Studies were included if they collected empirical data on expansions or restrictions of prescription drug coverage and if they reported clinical outcomes. We found 23 studies demonstrating that broader prescription drug insurance reduces use of other health care services and has a positive impact on patient outcomes. Coverage gaps or caps on drug insurance generally led to worse outcomes. States should consider implementing the Affordable Care Act expansions in drug coverage to improve the health of low-income patients receiving state-based health insurance. (Am J Public Health. Published online ahead of print December 18, 2014: e1-e14. doi:10.2105/AJPH.2014.302240).
BACKGROUND: Growing expenditures on prescription medicines represent a major challenge to many health systems. Cap and co-payment policies are intended as an incentive to deter unnecessary or marginal utilisation, and to reduce third-party payer expenditures by shifting parts of the financial burden from insurers to patients, thus increasing their financial responsibility for prescription medicines. Direct patient payment policies include caps (maximum numbers of prescriptions or medicines that are reimbursed), fixed co-payments (patients pay a fixed amount per prescription or medicine), co-insurance (patients pay a percentage of the price), ceilings (patients pay the full price or part of the cost up to a ceiling, after which medicines are free or are available at reduced cost) and tier co-payments (differential co-payments usually assigned to generic and brand medicines). This is the first update of the original review.
OBJECTIVES: To determine the effects of cap and co-payment (cost-sharing) policies on use of medicines, healthcare utilisation, health outcomes and costs (expenditures).
SEARCH METHODS: For this update, we searched the following databases and websites: The Cochrane Central Register of Controlled Trials (CENTRAL) (including the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register, Cochrane Library; MEDLINE, Ovid; EMBASE, Ovid; IPSA, EBSCO; EconLit, ProQuest; Worldwide Political Science Abstracts, ProQuest; PAIS International, ProQuest; INRUD Bibliography; WHOLIS, WHO; LILACS), VHL; Global Health Library WHO; PubMed, NHL; SCOPUS; SciELO, BIREME; OpenGrey; JOLIS Library Network; OECD Library; World Bank e-Library; World Health Organization, WHO; World Bank Documents & Reports; International Clinical Trials Registry Platform (ICTRP), WHO; ClinicalTrials.gov, NIH. We searched all databases during January and February 2013, apart from SciELO, which we searched in January 2012, and ICTRP and ClinicalTrials.gov, which we searched in March 2014.
SELECTION CRITERIA: We defined policies in this review as laws, rules or financial or administrative orders made by governments, non-government organisations or private insurers. We included randomised controlled trials, non-randomised controlled trials, interrupted time series studies, repeated measures studies and controlled before-after studies of cap or co-payment policies for a large jurisdiction or system of care. To be included, a study had to include an objective measure of at least one of the following outcomes: medicine use, healthcare utilisation, health outcomes or costs (expenditures).
DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed study limitations. We reanalysed time series data for studies with sufficient data, if appropriate analyses were not reported.
MAIN RESULTS: We included 32 full-text articles (17 new) reporting evaluations of 39 different interventions (one study - Newhouse 1993 - comprises five papers). We excluded from this update eight controlled before-after studies included in the previous version of this review, because they included only one site in their intervention or control groups. Five papers evaluated caps, and six evaluated a cap with co-insurance and a ceiling. Six evaluated fixed co-payment, two evaluated tiered fixed co-payment, 10 evaluated a ceiling with fixed co-payment and 10 evaluated a ceiling with co-insurance. Only one evaluation was a randomised trial. The certainty of the evidence was found to be generally low to very low.Increasing the amount of money that people pay for medicines may reduce insurers' medicine expenditures and may reduce patients' medicine use. This may include reductions in the use of life-sustaining medicines as well as medicines that are important in treating chronic conditions and medicines for asymptomatic conditions. These types of interventions may lead to small decreases in or uncertain effects on healthcare utilisation. We found no studies that reliably reported the effects of these types of interventions on health outcomes.
AUTHORS' CONCLUSIONS: The diversity of interventions and outcomes addressed across studies and differences in settings, populations and comparisons made it difficult to summarise results across studies. Cap and co-payment polices may reduce the use of medicines and reduce medicine expenditures for health insurers. However, they may also reduce the use of life-sustaining medicines or medicines that are important in treating chronic, including symptomatic, conditions and, consequently, could increase the use of healthcare services. Fixed co-payment with a ceiling and tiered fixed co-payment may be less likely to reduce the use of essential medicines or to increase the use of healthcare services.
BACKGROUND: The global prevalence of diabetes is increasing. Medications are a recommended strategy to control hyperglycaemia. However, patient adherence can be variable, impacting health outcomes. A range of interventions for patients with type 2 diabetes have focused on improving treatment adherence. This review evaluates the impact of these interventions on adherence to anti-diabetic medications and focuses on the methods and tools used to measure adherence.
METHOD: Medline, Embase, CINAHL, IPA, PUBmed, and PsychINFO were searched for relevant articles published in 2000-2013, using appropriate search terms.
RESULTS: Fifty two studies addressing adherence to anti-diabetic medications in patients with type 2 diabetes met the inclusion criteria and were reviewed. Each study was assessed for research design, method(s) used for measuring medication adherence, and impact of intervention on medication adherence and glycaemic control. Fourteen studies were published in 2000-2009 and 38 in 2010-2013. Twenty two interventions led to improvements in adherence to anti-diabetic medications, while only nine improved both medication adherence and glycaemic control. A single strategy could not be identified which would be guaranteed to improve anti-diabetic medication adherence consistently. Nonetheless, most interventions were successful in influencing one or more of the outcomes assessed, indicating the usefulness of these interventions under certain circumstances. Self-report, particularly the Summary of Diabetes Self-Care Activities questionnaire was the most commonly used tool to assess medication adherence, although other self-report tools were used in more recent studies. Overall, there was a slight increase in the number of studies that employed multiple methods to assess medication adherence in studies conducted after 2008.
CONCLUSION: The diversity of interventions and adherence measurements prevented a meta-analysis of the impact of interventions on adherence to therapy, highlighting the need for more consistency in methods in the area of adherence research. Whilst effective interventions were identified, it is not possible to conclude on an effective intervention that can be generalised to all patients with type 2 diabetes.
OBJECTIVES: To evaluate the effects of health insurance benefit designs that introduced or increased the price difference between prescription drugs representing potential clinical substitutes.
STUDY DESIGN: Systematic review of peer-reviewed articles.
METHODS: Using English-language articles listed in PubMed between 1980 and 2012, we identified articles meeting our inclusion criteria and minimum methodological standards. We compared findings regarding the immediate patient response, total spending, and health outcomes after implementing the price change.
RESULTS: Among the 31 articles identified, the mechanisms varied for creating the price differential between prescription drug substitutes, though they most frequently involved tiered formularies (19) or reference pricing (10). While nearly all studies (29 of 31) reported on patient responses to price changes, only 5 articles comprehensively assessed patient price responses, total spending, and health outcomes. Several studies found that some patients switched to cheaper drugs, but out-of-pocket spending increased on average, suggesting that other patients continued using the more expensive drug (ie, cost shifting to patients). Few studies examined the degree of heterogeneity in behavior responses, especially between patient cohorts for whom the substitute drugs had varying value. Some studies observed long-term effects, but most had limited post intervention observation periods.
CONCLUSIONS: Differential cost-sharing designs influence drug use behavior, but there is limited evidence on how these designs affect the overall value of received care. The existing literature provides limited guidance for policy makers or organizational leaders to design benefits. We offer suggestions for future studies to inform policy and practice.
Objective: To review international policies to control expenditure on pharmaceuticals by influencing the behaviour of patients and providers and regulating the pharmaceutical industry. Method: Systematic review of experimental and quasi-experimental studies. Published studies were identified with an electronic search strategy using MEDLINE and EMBASE from 1980 to May 2012. Studies were eligible if they assessed the effect of policies aimed at influencing the behaviour of patients and providers, and regulating the pharmaceutical industry. Outcome measures included pharmaceutical expenditure, prices or utilization; other resource use relating to pharmaceuticals; and health outcomes and patients’ or providers’ behaviour relating to pharmaceutical use. Quality assessment criteria for each study design were developed based on the standard criteria recommended by the Cochrane Effective Practice and Organisation of Care (EPOC) group. The review includes studies based on randomized controlled trials and rigorous quasi-experimental designs (interrupted time-series and controlled before-and-after studies). Studies were excluded if they were conducted within a single hospital or practice; related to pharmaceutical care services or disease management; had less than 6 months of follow-up period (or less than 12 months overall for interrupted time series); if data in controlled before-and-after studies were not collected contemporaneously or if no rationale was stated for the choice of control group; or if relevant and interpretable data were not presented. Results: A total of 255 studies met the inclusion criteria for this review. The majority of the studies relating to patients evaluated cost sharing interventions such as user charges (52 studies). User charges do reduce utilization of pharmaceuticals, and reduce public expenditure by shifting costs to patients. But they reduce the use of essential as well as nonessential drugs, and without adequate exemptions they affect vulnerable groups disproportionately. The majority of studies relating to doctors evaluated the effects of educational approaches (78 studies), reimbursement restrictions (48 studies) and incentive systems (22 studies). Evidence on these policies is of mixed quality. It appears possible to influence prescribing modestly, through various means, but it is essential that messages to prescribers are based on good evidence of effectiveness and cost-effectiveness. Twenty-nine studies related to industry regulation, and they were of mixed quality. Evidence from studies of reference pricing suggests that this may result in cost savings. These are, however, achieved not by companies reducing or restraining prices, or by reductions in the overall volume of prescriptions, but by some shifts in use and shifting costs to patients, with consequent adverse effects on the equity of access to medicines. Other price and profit controls remain almost completely lacking in evaluative evidence. Conclusions: It may be that the undesirable consequences of policies influencing patients, particularly user charges, can outweigh the benefits. To influence demand for pharmaceuticals, it is more appropriate to influence prescribing doctors and although interventions to improve prescribing practice have been developed, they often achieve relatively modest benefits and sometimes at high cost. Good evaluative evidence related to industry regulation is scarce despite its policy importance.
BACKGROUND: Prescription drugs are used in people with hypertension, diabetes, and cardiovascular disease to manage their illness. Patient cost sharing strategies such as copayments and deductibles are often employed to lower expenditures for prescription drug insurance plans, but the impact on health outcomes in these patients is unclear.
OBJECTIVE: To determine the association between drug insurance and patient cost sharing strategies on medication adherence, clinical and economic outcomes in those with chronic diseases (defined herein as diabetes, hypertension, hypercholesterolemia, coronary artery disease, and cerebrovascular disease).
METHODS: Studies were included if they examined various cost sharing strategies including copayments, coinsurance, fixed copayments, deductibles and maximum out-of-pocket expenditures. Value-based insurance design and reference based pricing studies were excluded. Two reviewers independently identified original intervention studies (randomized controlled trials, interrupted time series, and controlled before-after designs). MEDLINE, EMBASE, Cochrane Library, CINAHL, and relevant reference lists were searched until March 2013. Two reviewers independently assessed studies for inclusion, quality, and extracted data. Eleven studies, assessing the impact of seven policy changes, were included: 2 separate reports of one randomized controlled trial, 4 interrupted time series, and 5 controlled before-after studies.
FINDINGS: Outcomes included medication adherence, clinical events (myocardial infarction, stroke, death), quality of life, healthcare utilization, or cost. The heterogeneity among the studies precluded meta-analysis. Few studies reported the impact of cost sharing strategies on mortality, clinical and economic outcomes. The association between patient copayments and medication adherence varied across studies, ranging from no difference to significantly lower adherence, depending on the amount of the copayment.
CONCLUSION: Lowering cost sharing in patients with chronic diseases may improve adherence, but the impact on clinical and economic outcomes is uncertain.
BACKGROUND: There is extensive literature demonstrating that formulary restrictions reduce the pharmacy costs and utilization of restricted drugs. However, some research suggests that there may be unintended consequences of formulary restrictions on other patient outcomes. While several literature reviews have assessed the relationship between formulary restrictions and medication adherence, clinical outcomes, economic outcomes, or health care resource utilization, these reviews were either not systematic, were conducted more than 5 years ago, or did not assess the aggregate directional impact of the relationships.
OBJECTIVE: To conduct a systematic literature review assessing the direction (positive, negative, or neutral) of the relationship between managed care formulary restrictions (including step therapy, cost sharing, prior authorization, preferred drug lists, and quantity limits) on medication adherence, clinical outcomes, economic outcomes, and health care resource utilization.
METHODS: Articles published in 1993 or later were identified from PubMed using 2 lists of search terms. List A included 12 formulary restriction terms and List B included 12 patient outcomes terms, resulting in 144 unique search term combinations. Each article was evaluated by 2 investigators against the following exclusion criteria using a stepwise approach: (a) the article was a commentary or review article; (b) the article did not assess the impact of managed care formulary restrictions on outcomes; and (c) the study was conducted outside the United States. The total number of studies was reported by formulary restriction type. Next, the total number of outcomes reported in each study was summed to conduct an outcomes-level analysis. The outcomes were categorized by type of outcome (medication adherence, clinical, economic, or health care resource utilization) and direction of association (positive, negative, or neutral/not significant) based on the relationship reported in each study. The frequencies of each type of outcome were stratified by direction of association.
RESULTS: A total of 93 studies were included from 811 reviewed articles. Cost sharing was the most commonly assessed type of formulary restriction (60.2% of included articles), followed by prior authorization (21.5%). Of the 262 patient outcomes assessed, medication adherence was the most common (120 outcomes, 45.8%). Overall, formulary restrictions were most frequently negatively correlated with outcomes (130 outcomes, 49.6%). When outcome type was stratified by direction of association, 68.3% (82/120) of medication adherence outcomes were negative. The direction of association of economic outcomes (n = 59) with formulary restrictions was split between neutral (37.3%), positive (33.9%), and negative (28.8%). Health care resource utilization outcomes (n = 72) had no association with formulary restrictions in 50.0% of the outcomes assessed. There were 11 clinical outcomes identified in the literature review.
CONCLUSIONS: There is a strong evidence base demonstrating a negative correlation between formulary restrictions on medication adherence outcomes. Additional research on commonly used formulary restrictions, specifically prior authorization and step therapy, as well as on the association between formulary restrictions and clinical outcomes, is warranted.
Drug insurance schemes are systems that provide access to medicines on a prepaid basis and could potentially improve access to essential medicines and reduce out-of-pocket payments for vulnerable populations.
, OBJECTIVES:
To assess the effects on drug use, drug expenditure, healthcare utilisation and healthcare outcomes of alternative policies for regulating drug insurance schemes.
, SEARCH METHODS:
We searched CENTRAL, MEDLINE, Embase, nine other databases, and two trials registers between November 2014 and September 2020, including a citation search for included studies on 15 September 2021 using Web of Science. We screened reference lists of all the relevant reports that we retrieved and reports from the Background section. Authors of relevant papers, relevant organisations, and discussion lists were contacted to identify additional studies, including unpublished and ongoing studies.
, SELECTION CRITERIA:
We planned to include randomised trials, non-randomised trials, interrupted time-series studies (including controlled ITS [CITS] and repeated measures [RM] studies), and controlled before-after (CBA) studies. Two review authors independently assessed the search results and reference lists of relevant reports, retrieved the full text of potentially relevant references and independently applied the inclusion criteria to those studies. We resolved disagreements by discussion, and when necessary by including a third review author. We excluded studies of the following pharmaceutical policies covered in other Cochrane Reviews: those that determined how decisions were made about which conditions or drugs were covered; those that placed restrictions on reimbursement for drugs that were covered; and those that regulated out-of-pocket payments for drugs.
, DATA COLLECTION AND ANALYSIS:
Two review authors independently extracted data from the included studies and assessed risk of bias for each study, with disagreements being resolved by consensus. We used the criteria suggested by Cochrane Effective Practice and Organisation of Care (EPOC) to assess the risk of bias of included studies. For randomised trials, non-randomised trials and controlled before-after studies, we planned to report relative effects. For dichotomous outcomes, we reported the risk ratio (RR) when possible and adjusted for baseline differences in the outcome measures. For interrupted time series and controlled interrupted time-series studies, we computed changes along two dimensions: change in level; and change in slope. We undertook a structured synthesis following the EPOC guidance on this topic, describing the range of effects found in the studies for each category of outcomes.
, MAIN RESULTS:
We identified 58 studies that met the inclusion criteria (25 interrupted time-series studies and 33 controlled before-after studies). Most of the studies (54) assessed a single policy implemented in the United States (US) healthcare system: Medicare Part D. The other four assessed other drug insurance schemes from Canada and the US, but only one of them provided analysable data for inclusion in the quantitative synthesis. The introduction of drug insurance schemes may increase prescription drug use (low-certainty evidence). On the other hand, Medicare Part D may decrease drug expenditure measured as both out-of-pocket spending and total drug spending (low-certainty evidence). Regarding healthcare utilisation, drug insurance policies (such as Medicare Part D) may lead to a small increase in visits to the emergency department. However, it is uncertain whether this type of policy increases or decreases hospital admissions or outpatient visits by beneficiaries of the scheme because the certainty of the evidence was very low. Likewise, it is uncertain if the policy increases or reduces health outcomes such as mortality because the certainty of the evidence was very low.
